Myelitis is an uncommon but well-described complication of SLE. It can be a presenting sign of SLE. The rapid clinical deterioration and imaging findings of edema within the spinal cord are similar to those seen in transverse myelitis of other etiologies. Outcome varies, with about half of SLE cases of transverse myelitis reported to have complete recovery, 30% with partial recovery, and 20% with no recovery (4).

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Figure 6. Myelitis in SLE. A woman in her late 30s present with acute onset paraplegia 6 years after the diagnosis of SLE. She was treated with cyclophosphamide and corticosteroids but failed to regain any significant lower extremity motor function. Sagittal T1-weighted image (A) is unremarkable. After intravenous gadolinium administration, sagittal T1-weighted image (B) shows enhancement in the lower thoracic spinal cord (arrow). Corresponding high signal intensity is seen on the sagittal T2-weighted image (C).

Focal White Matter Lesions

Small areas of T2 prolongation in cerebral white matter are common in SLE. The correlation with clinical signs and symptoms of CNS disease is unclear (5). Most likely these are related to chronic changes in the brain rather than an acute event. However, in the patient with an acute presentation, diffusion-weighted imaging can be very helpful in distinguishing small, acute infarcts from chronic changes. The pathologic basis of these white matter lesions is also unclear. These are not usually due to an underlying vasculitis. Despite SLE often being included in lists of cerebral vasculitides, few SLE patients have true vasculitis. Rather, SLE is often accompanied by a bland, small vessel vasculopathy. In our experience, small areas of T2 hyperintensity are very common in SLE patients and are most often seen in subcortical white matter.

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Figure 7. White matter changes in SLE. A 35-year-old woman with SLE presented with numbness in the left upper and lower extremities. Diffusion-weighted imaging was negative, but FLAIR images (A, B, C, D) show scattered foci of hyperintensity in subcortical and periventricular white matter.